1. Technical Field
The present invention relates generally to migrating a database, and more particularly, to migrating a database between a source server and a target server while providing transaction services.
2. Related Art
Moving a database from one server to another is useful for a number of reasons. One reason a database migration is required is to allow for installation, maintenance or repair of associated hardware or software. In this case, it is helpful to migrate the database to a temporary location, e.g., server, while work is completed. For instance, most relational database management systems (RDBMS) cannot support reorganization in an active or online mode. A database migration may also be necessary to increase storage or processing capability, or because of a relocation of a data center perhaps due to a corporate move.
Relative to current e-commerce, database migration has been found advantageous to increase access speed where end users are geographically dispersed. That is, having data closer to the end users provides faster database access, e.g., because of increased network speeds. One example of this model is the common practice of having hypertext markup language (HTML) caching servers implemented closer to end users to increase performance. In this case, however, each user has limited access to the database.
Today, however, more services require continuous access to the database. The application service provider (ASP) field is one area where this attribute is desired. In this industry, an end-user connects remotely through their local Internet service provider (ISP) and accesses an ASP application running on the ASP's server. Many ASP's provide applications having a high degree of interaction with the database. Since each user (e.g., organization receiving service from ASP) is accessing an application and, typically, has their own personalized access to the application, the user is constantly viewing, modifying, and adding to data sitting in the database. Since even more interaction with the database is provided under this and similar models, it is increasingly advantageous to have the database as close as possible to users to increase access speeds and improve transaction service. Transaction services may be the providing of any conduct relative to an application and/or information.
A problem that arises relative to providing continuous access to an active (e.g., online) database and migrating the database to be closer to users, is that the service down time conventionally required for database migration is unacceptable. This is especially the case where a database migration takes a large amount of time, e.g., because of the database size. Another problem relative to transfer of an active database is assuring that the database implemented at the new location is synchronized with the source database when the new location is activated.
In view of the foregoing, there is a need in the art for a system and method for migrating an active database from a source server to a target server while continuing to provide transaction service.